Looking first at FIGS. 1 and 2, the meniscus 5 is a piece of cartilage located in the knee joint, between the top of the tibia 10 and the bottom of the femur 15. Meniscus 5 serves to facilitate stable movement of the tibia and femur relative to one another, and to absorb shock and to spread load.
Meniscus 5 is frequently damaged (e.g., torn) as the result of injury and/or accident. See, for example, the tear 20 shown in FIG. 3. A damaged meniscus can impede proper motion of the knee joint and cause pain, among other things.
At one time, the standard treatment for a badly damaged meniscus was the partial or complete removal of the meniscus. However, it was subsequently recognized that patients having a partial or complete removal of their meniscus frequently suffered from long term joint problems, e.g., arthritis.
The current trend is toward repairing a damaged meniscus, rather than removing part or all of the meniscus. This approach typically requires that tears in the meniscus be closed. There are currently two approaches to closing a tear in the meniscus: suturing and fastening.
Suturing a tear in the meniscus has heretofore been technically difficult. This is because the knee joint is a relatively tight space and has limited access points, thus making it hard to maneuver suturing instruments and visualization devices. In addition, there are delicate blood vessels and nerves adjacent to the knee joint (e.g., at the back of the knee) which can be easily damaged, particularly by the sharp needles used to place the suture.
Due to the technical difficulties of suturing, fasteners have been developed to close a meniscal tear. Many different types of meniscal fasteners have been produced, e.g., arrows, tacks, T-bars, barbs-and-sutures, screws, etc. However, all of the fasteners developed to date tend to suffer from one or more disadvantages. Among these is the common—and quite significant—disadvantage associated with positioning a rigid component within the interior of the knee. More particularly, all of the fasteners developed to date incorporate at least one rigid component into their design. If the rigid component is not properly positioned at the time of deployment, and/or if the rigid component should subsequently migrate out of position, serious joint abrasion can result.
As a result, there is a significant need for a new and improved method and apparatus for meniscal repair.